Recently, communication systems have included the ability to send and receive information about the availability (e.g., presence) of users of the communication systems. The availability information indicates if a user has indicated that they are available for contact. For example, when a user first logs in to a communication system, they may be listed as available. Later, the user may select an option to indicate that they are busy and are not available for communication.
Communication systems provide the ability to establish whitelists and blacklists regarding which other users are authorized to receive information about the user's presence. Blacklists indicate which users are to be blocked from receiving presence information. Whitelists indicate which users are allowed to receive presence information (e.g., when the user blocks all users from receiving presence information by default and then identifies certain areas to receive the pressure information).